How Filipino Fishers Use Traditional Knowledge in Identifying Species of Juvenile Mangrove Crabs for Grow-out Culture

Mangrove crab growers in the Philippines still rely on wild-caught late instar to early juvenile mangrove crablets, as supplies from hatcheries are limited. Any batch of crablets caught from the wild is a mix of the three native species under the genus Scylla. Scylla species have different growth rates. Since grow-out culture depends heavily on species' growth, growers should be able to distinguish the species as early as the juvenile stage, which is taxonomically difficult. This study was done to consolidate low-cost traditional identification techniques for juvenile Scylla from fishers of the Philippines for future validation. Focused group discussions were done in fishing communities from Bataan, Pangasinan, and Cagayan on the island of Luzon. The study was continued through online surveys, as travel was restricted due to the Covid-19 pandemic. Results indicate that 70.58% of respondents identify the species of crabs by looking at their claws and 55.88% observe the color of the crabs. Almost half, or 41.17% of respondents, consider the width and size of the carapace. Unique methods in certain Philippine regions include observation of the behavior patterns, carapace texture, rate of weight gain, and seasonality. Validation of the traditional practices identified in this study would result in a reliable "at-a-glance" method of identifying juvenile Scylla in the Philippines, which would shorten the culture period, improve production gains, and manage local populations.

Bioakumulasi Logam Berat Timbal (Pb) dan Kadmium (Cd) pada Organ Timpakul Periopthalmodon schlosseri dan Boleopthalamus boddarti di Desa Kuala Tambangan

Heavy metals found in water bodies will accumulate in sediments and bodies of aquatic biota both diffusion and through the food chain. This study was conducted to determine the bioaccumulation of heavy metals lead and cadmium in the organs of mudskipper P. schlosseri and B. boddarti, water, sediment, and small mangrove crabs as a food supplement. The collection was carried out in the Kuala Tambangan village by means of a purposive sample. The process of analysis of heavy metals is carried out on the gills, skin, liver, kidneys and embalmed meat. Surgical implants were analyzed using the ASS method. The first test results were the highest Pb metal 12.49 mg / kg and Cd 5.30 mg / kg in the kidney of P. schlosseri. The results of the analysis on the kidneys of B. boddarti species contained the highest Pb content of 7.56 mg / kg and Cd 3.94 mg / kg. The second test results of analysis of the content of heavy metals Pb and Cd in undetectable tympanic organs that is <0.24 mg / kg for all organs measured. The testing of the three Pb and Cd metal contents was partially undetectable, some containing heavy metals but still below the quality standard, except that the content of Cd in the liver of P. Schlosseri ie 0.364 mg / kg had exceeded the normal threshold. Pb metal content in tide water reaches 0.07 ml / l and passes the quality standard, while the Pb and Cd content in sediment and mangrove crabs as food chain is still below the standard and some heavy metals are not detected.

From Mangrove to Fork: Metal Presence in the Guayas Estuary (Ecuador) and Commercial Mangrove Crabs

Mangrove wetlands provide essential ecosystem services such as coastal protection and fisheries. Metal pollution due to industrial and agricultural activities represents an issue of growing concern for the Guayas River Basin and related mangroves in Ecuador. Fisheries and the related human consumption of mangrove crabs are in need of scientific support. In order to protect human health and aid river management, we analyzed several elements in the Guayas Estuary. Zn, Cu, Ni, Cr, As, Pb, Cd, and Hg accumulation were assessed in different compartments of the commercial red mangrove crab Ucides occidentalis (hepatopancreas, carapax, and white meat) and the environment (sediment, leaves, and water), sampled at fifteen sites over five stations. Consistent spatial distribution of metals in the Guayas estuary was found. Nickel levels in the sediment warn for ecological caution. The presence of As in the crabs generated potential concerns on the consumers’ health, and a maximum intake of eight crabs per month for adults is advised. The research outcomes are of global importance for at least nine Sustainable Development Goals (SDGs). The results presented can support raising awareness about the ongoing contamination of food and their related ecosystems and the corresponding consequences for environmental and human health worldwide.

Analysis Of Types Of Carotenoid Pigments In Crab Sesarmops sp From Manado By Coast

Carotenoid pigments are a group of pigments that are yellow, orange, and red-orange in color. Pigments are natural dyes found in plants and animals, extracts of carotenoid pigments can be separated by chromatographic methods where the common chromatographic methods in determining the type of pigment are Column Chromatography (CC) and Thin Layer Chromatography (TLC). The purpose of this study was to determine the types of pigments contained in the carapace extract of the male crab Sesarmops sp. The Sesarmops sp crab has a brown dorsal carapace with blackish-brown leg spots known as mangrove crabs. Crabs in the Sesarmidae family have a carapace formation and wide legs, do not have swimming legs, and have a pair of claws that are faded purple, the presence of these colors can be identified as containing carotenoid pigments. The results of this study obtained the content of carotenoid pigment 25.2 g/gr and the value of the concentration of carotenoid pigment in the male crab extract Sesarmops sp 10.99 g. The results of the separation of the total pigment extract using column chromatography obtained the types of pigments -carotene, Ekinenon, Zeaxanthin, and Astaxanthin. Keywords: Column Chromatography (CC); Carotenoids; Sesarmops sp AbstrakPigmen karotenoid adalah sekelompok pigmen yang berwarna kuning, oranye dan merah oranye. Pigmen adalah zat warna alami yang terdapat pada tumbuhan dan hewan, ekstrak pigmen karotenoid dapat dipisahkan dengan metode kromatografi yang dimana metode kromatografi umum dalam menentukan jenis pigmen adalah Kromatografi Kolom (KK) dan Kromatografi Lapis Tipis (KLT). Tujuan dari penelitian ini untuk mengetahui jenis-jenis pigmen apa saja yang terdapar pada ekstrak karapas kepiting jantan Sesarmops sp. Kepiting Sesarmops sp memiliki karapas dorsal bewarna coklat dengan bintik kaki coklat kehitaman yang dikenal sebagai kepiting mangrove. Kepiting dalam keluarga sesarmidae memiliki bentukan karapas dan kaki yang lebar tidak memiliki kaki renang serta memiliki sepasang capit berwarna ungu pudar, adanya warna tersebut kepiting dapat diidentikasikan mengandung jenis pigmen karotenoid. Dari hasil penelitian ini mendapatkan kandungan pigmen karotenoid 25,2 dan nilai konsentrasi pigmen karotenoid pada ekstrak kepiting jantan Sesarmops sp 10,99 . Hasil pemisahan dari ekstrak pigmen total menggunakan kromatografi kolom didapatkan jenis pigmen β-karoten, Ekinenon, Zeaxantin dan Astaxantin

Structure of Hard And Soft Carapace Exoskeleton Biomaterial Through SEM-EDXRS at Various Stages of Development Scylla paramamosain Mud Crab

Crustacean carapace has various functions which can be seen from the composition of the biomaterial in it. Various concentrations of inorganic biomaterial elements were investigated from the hard carapace and the newly molted (soft-shelled) (Scylla paramamosain) with SEM-EDXRS (scanning electron microscopy-Energy Dispersive X-ray Spectrometer) technique. This study traced the composition of the inorganic elements of the premolt, postmolt, intermolt and soft (exuvium) crab hard carapace tissue of mangrove crabs from the point of view. Various stages of development. Important elements such as C, O2, Mg, P, Ca, S, Na, Si, Cl, and others, are reabsorbed from the carapace into the body tissues to fulfill further needs in soft-shelled crabs and are reused to some extent during formation new carapace. This study provides evidence that, inorganic elements in freshly molted soft carapace crabs are less common than hard carapace crabs